1. Field of the Invention
The present invention belongs to the field of antagonists of the endothelin receptor. Endothelin (ET-1) itself is an endothelium-derived potent vasoconstrictor peptide consisting of 21 amino acids. The unusually prolonged vasoconstriction induced by endothelin in the presence or absence of extracellular Ca.sup.2+ suggests that the action of this peptide may profoundly influence blood pressure regulation under normal and pathophysiological conditions. As described further below, endothelin also has a number of other physiological effects, and antagonists which bind to its receptor are thus expected to have advantageous pharmacological properties and corresponding therapeutic benefits.